Recommended Coverage

"My sister Chris is gay. Certainly that whole coming out process was a testing time for her and our family. It forces all of our to confront various things in our hearts.

"Good on Chris for her courage, she and I have polite, respectful and vigorous discussion on this."

Meanwhile, Foreign Minister Bob Carr says the parliamentary numbers may be shifting in support of legalising same-sex marriage.

"I think any observer would say there's an underlying trend as members of parliament give it more consideration and listen to the arguments to legalising same-sex marriage," Senator Carr told ABC radio on Tuesday.

He also acknowledged there was "considerable support" for legalising same-sex marriage among coalition MPs.

Mr Rudd said any legal recognition for gay marriage should make religious institutions exempt from having to change their own practices.

Last September Mr Rudd was one of 98 MPs who voted against a marriage equality bill.

But on Monday he recounted a recent conversation with a gay, "God-botherer" former political staffer who told him he hoped to get married to another man one day.

The encounter led Mr Rudd to rethink his position.

"I have come to the conclusion that church and state can have different positions and practices on the question of same sex marriage," Mr Rudd said. "I believe the secular Australian state should be able to recognise same sex marriage."

News.com.au's Privacy Policy includes important information about our collection, use and disclosure of your personal information (including to provide you with targeted content and advertising based on your online activities). It explains that if you do not provide us with information we have requested from you, we may not be able to provide you with the goods and services you require. It also explains how you can access or seek correction of your personal information, how you can complain about a breach of the Australian Privacy Principles and how we will deal with a complaint of that nature.

A NOTE ABOUT RELEVANT ADVERTISING: We collect information about the content (including ads) you use across this site and use it to make both advertising and content more relevant to you on our network and other sites.